CN105937883B

CN105937883B - Device and method for inspecting closures

Info

Publication number: CN105937883B
Application number: CN201610394556.2A
Authority: CN
Inventors: M·马伊; D·伯尔茨
Original assignee: Robert Bosch GmbH
Current assignee: Xingdeke Technology Co ltd
Priority date: 2015-03-03
Filing date: 2016-03-03
Publication date: 2020-05-19
Anticipated expiration: 2036-03-03
Also published as: CN105937883A; ITUB20161044A1; DE102015203726B4; DE102015203726A1

Abstract

The invention relates to a device and a method for testing a closure (14), wherein the closure (14) closes a container (12), wherein an evaluation unit (23) is provided for determining a quality criterion (40, 47), in particular a gap size between the closure (14) and the container (12), wherein at least one sensor (18) is provided for determining a height profile of the closure (14), wherein at least one output signal of the sensor (18) is supplied to the evaluation unit (23), which determines the quality criterion (40, 47) from the output signal of the sensor (18).

Description

Device and method for inspecting closures

Technical Field

The invention relates to a device and a method for inspecting closures.

Background

The invention proceeds from a device and a method for inspecting closures of the type according to the independent claims. In pharmaceutical manufacturing, closures are typically placed onto containers (e.g., bottles). In a further step, the closure and the container are connected by means of a cap. A gap may be formed between the closure and the container. The height of this gap is critical for pharmaceutical manufacturing, since the product may be contaminated in the worst case due to an excessively large gap. Accurate checking of the gap is important because containers with small gaps can still be accepted to avoid unnecessary waste.

A device of this type is known from WO 2012/061441 a 1. In this case, the closure region to be detected reaches the path formed by the laser and the corresponding receiver. The laser light is emitted through the closure area from the side about the longitudinal axis of the container. However, it must be ensured at the precise trigger time that the measurement is only initiated when the object to be detected is located in the laser band. Fluctuations in the trigger signal can lead to problems, so that this must be taken into account when setting the trigger time point and the measurement only starts a little further inside the closure. As a result, the size of the gap between the container and the closure cannot be reliably determined on the outermost rim of the closure. Identification of a tipped closure in a container is also problematic.

Disclosure of Invention

The object of the invention is to detect the size of the gap between the container and the closure with high accuracy. This object is achieved by the features of the independent claims.

In contrast, the device according to the invention for checking the region of a closure according to the features of the independent claim has the advantage that tipping of the closure is reliably detected. The tipping over of the closure or the corresponding height profile then enters into the calculation of a quality criterion, for example the size of the gap between the container and the closure. This can be achieved according to the invention in that at least one sensor for determining the height profile, in particular of the closure, is provided. The device with the features of independent claim 1 enables: in addition to the orientation of the closure, a gap between the upper edge of the container and the lower edge of the closure is defined at defined support points. The maximum encircling gap size can then be determined from the result.

It is particularly advantageous to combine the output signal of the sensor with the output signal of a sensor unit which detects the closure region, preferably optically.

As the closure is typically constructed of a flexible material. That is, it cannot be assumed that the lower container plate has a flat surface. The lower closure plate may deform just in the event that the closure is tipped or bent. In the prior art, the plug slit is passed as a cut line along the optical axis, along the light line in the case of a camera system, the height of which is underestimated in the case of a bent or overturned closure plate, in contrast to the case of the prior art. Since the gaps in the shadow image are reduced due to the inverted orientation of the closure in the container, it is the responsibility of the two-dimensional projection of the closure in a three-dimensional orientation. According to the invention, the orientation of the closure can now be determined and the gap size (preferably between the upper edge of the container and the lower edge of the closure panel) can be determined at defined support points. The maximum circumferential gap size can thus be determined as a quality criterion. Whereby a better accuracy can be obtained compared to the prior art.

The rotation of the container can also be cancelled during the inspection. This rotation can be mechanically laborious. Furthermore, there is the risk that: the closure is lost due to said rotation or most of the liquid product comes into contact with the closure. Since such a rotation is no longer required in the device according to the features of claim 1, this device can also be easily integrated into existing installations.

Furthermore, the use of sensors for determining the height profile can also be used for other inspection possibilities and for defining other quality criteria. For example, the packaging material on the surface of the closure can be checked for specific markings. This ensures that the correct packaging material is used for the respective load (charge). Furthermore, the surface of the closure plate can be checked for damage or deformation by means of the ascertained measurement data. Thus, in addition, the reliability of the products, which is of particular importance in the pharmaceutical industry, can be increased.

In a further embodiment, it is provided that a triangulation-based system is used as a sensor for determining the height profile. The surface of the closure to be detected is thus guided step by step along the sensing region of the, for example, linear triangulation laser, so that the entire surface or height profile can be sensed in a simple manner.

In a particularly expedient development, the height profile of the sensing closure is combined with the determination of the gap size at defined support points of the optical sensor unit. By intelligent combination of the measurements, the size of the gap between the upper rim of the container and the lower rim of the closure panel can be determined at any arbitrary location on the periphery of the closure. In this way, the maximum gap can be determined more accurately than in the systems known to date, in particular when the plug or closure is inclined or deformed. Thus, in addition, the rejection rate (Pseudoausschussraten) can be significantly reduced.

For this purpose, it is particularly preferred to use an algorithm in the evaluation software, which interpolates the gap size circumferentially from the three-dimensional height information on the basis of the gap size measured at the defined site or support site. In this case, the sensor unit and the sensor for determining the height profile are coupled to one another, for example on a central image processing computer, which can evaluate the information of both measurements in a combined manner. The mechanical positioning of the two systems is also matched to one another in order to be able to determine the positioning of the support site with respect to the three-dimensional height profile. The setting up of the system can be carried out, for example, by means of a setting model (Einstelldummies).

Further developments which meet the object are evident from the further dependent claims and from the description.

Drawings

Embodiments of the device for inspecting closures according to the invention are shown in the drawings and explained in detail below. The figures show:

figure 1 shows a schematic view of the structure of the overall system in top view,

figure 2 shows a schematic view of a sensor for determining the height profile in a side view,

figures 3 and 4 show schematic diagrams of a sensor unit for determining the size of the gap between the upper edge of the container and the lower edge of the closure plate at four support points in a top view and in a corresponding side view,

figures 5 and 6 show a schematic representation of the closure area with the support site in a side view and an associated top view,

FIG. 7 is a graphical representation of the combined measurement results.

Detailed Description

The containers 12 are fed to the conveying means 20 via the inlet section 28. The container 12 has been filled with a product, for example a liquid pharmaceutical product, at a previous, not shown work station and closed by a closure 14. The device shown in fig. 1 is used to check the closure area or to check the size of the gap formed between the container 12 and the closure 14. The transfer device 20 is configured, for example, as a transfer star. The conveying means 20 has a receptacle 22 on the outside, in which the container 12 can be fixed. The transfer device 20 rotates clockwise. Thus, the container 12 first reaches the sensing region of the sensor 18 for determining the height profile. The sensor 18 for determining the height profile is arranged above the conveying path of the containers 12. Illustratively, the sensor is configured linearly and at least partially covers the surface of the closure 14 that closes the container 12. The sensor 18 for determining the height profile is oriented with its longitudinal axis toward the center point of the conveying means 20 or perpendicular to the conveying direction of the containers 12. By further conveyance of the container 12, the sensor 18 for ascertaining the height profile senses the entire height profile of the surface of the closure 14, either by multiple scans or by successive scans. The output signal of the sensor 18 for determining the height profile is supplied to an evaluation unit 23. The analysis processing unit 23 also receives the signal of the sensor unit 24. The evaluation unit 23 thus determines a quality criterion. Preferably, the gap size 40, 47 between the closure 14 and the container 12 is used as a quality criterion. Information about the height profile of the closure 14 can also be considered as a quality criterion. The evaluation unit 23 determines the quality criterion 40, 47 at least from the output signal of the sensor 18 or from the height profile.

A sensor unit 24 is likewise arranged in the transport path of the containers 12. The closed containers 12 are brought into the sensing region of the sensor unit 24 by the conveying means 20, respectively. The sensor unit 24 is oriented relative to the container 12 and the closure 14 located therein such that the closure area is transmitted from the side with respect to the longitudinal axis of the container 12. The containers 12 are then conveyed further by the conveying means 20 and via the outfeed 30 into further processing stations not shown.

Fig. 2 shows a side view of the sensor 18 for determining the height profile in more detail. The sensor 18 shown in fig. 2 determines the height profile of the closure surface by means of triangulation. An effective triangulation method utilizes a light source, mostly a laser, which illuminates the object (here the enclosure 14) whose surface should be measured at an angle. Electronic image converters, mostly CCD or CMOS cameras or PSDs, record diffuse light. The emitted and reflected laser beams are schematically indicated with

reference numerals

15, 16. The sensor 18 therefore comprises at least means for generating a directed optical beam (in particular a laser beam 15, 16) and an optical sensor for sensing the beam reflected from the surface of the closure 14. The object-to-camera distance can thus be determined with knowledge of the beam direction and knowledge of the distance between the camera and the light source. The line from the camera to the light source and the two

beams

15, 16 that originate from and to the surface of the closure element form a triangle (triangulation). If the method is carried out in a grid or continuous motion, the surface topography or the height profile can be determined with high accuracy (up to 0.01 mm in the case of commercially available sensors).

The conveying means 20 move the container 12 with the placed closure 14 into the sensing region of the sensor 18 and the emitted

laser beams

15, 16. The correspondingly inclined surfaces of the enclosure 14 reflect the

laser beams

15, 16 in accordance with the inclination or curvature of the enclosure 14. Thus, the entire surface of the closures 14 is scanned and sensed in terms of height profile or orientation or inclination in the range of further conveyance of the containers 12 along the conveying direction 21. It is clear from this when and in what form the closure 14 is tilted relative to the generally horizontally arranged container 12. The corresponding inclination or curvature affects the gap size 40 between the container 12 and the closure 14.

Fig. 3 shows a sensor unit 24 for lateral transmission of the closure element region in a plan view and fig. 4 in a side view. The sensor unit 24 illustratively consists of at least one transmitter 34 and at least one receiver 32 that receives the emitted radiation as represented by arrows (e.g., in an optical zone). In the present exemplary embodiment, two emitters 34 are provided, which are each arranged offset by 90 ° with respect to one another. On the respectively opposite side, a receiver 32 is arranged, which is configured, for example, as a video camera. The container 12 with the closure 14 placed on is centered between the two irradiation zones. In a side view, it is clear that, based on the 2D projection of the emitted radiation in the camera or receiver 32, only the reduced gap size 36 is detected, which originates from the side of the closure region close to the transmitter 34. However, on the side facing the receiver 32, the gap dimension 40 is significantly larger. This maximum gap size 40, as is clear in fig. 5, may not be detectable if only a single measurement is made by the sensor unit 24. The output signal of the sensor unit 24 is therefore combined with the output signal of the sensor 18 for determining the height profile, as explained in more detail below.

In the embodiment according to fig. 3 and 4, the gap size 40 between the upper edge 39 of the container 12 and the lower edge 38 of the closure panel can now be sensed at four support points 43 (see also fig. 5). In particular, a contactless, preferably optical system is used as sensor unit 24. In this case, it may be, for example, a camera system or a laser-based system in which a laser band is projected into the region of the closure. However, other systems suitable for sensing the gap size 36 are also contemplated.

Fig. 5 shows a schematic view of the support point 43 at which the measurement of the gap size 40 or the measured quality criterion between the upper edge 39 of the container 12 and the lower edge 38 of the closure panel is carried out. In FIG. 5 is shown in relation to the container 12 or container flange

Closure 14 in the region of the inclination. The two arrows show at which point or which support point of the closure 14 the gap size 40 is determined. The determination of the gap size 40 is particularly advantageously carried out at the outermost points, i.e. at the lower edge 38 (see arrow and dashed line in fig. 5) of the closure 14 oriented toward the container 12 and at the upper edge 39 of the container 12 or container flange. In this way, it is also ensured that the support points 43 are ideally distributed equidistantly along the circumference when the closure is tilted. In the case of a two-transmitter-receiver system as shown in fig. 3, it is thus achieved that the four support points 43 are offset by 90 ° in each case. Each camera or each receiver 32 therefore senses two support points 43 with the associated gap size 40, which is determined at the outermost position to the left or to the right of the camera axis.

These four support points 43 are indicated in fig. 6 with corresponding reference numerals. The sensor unit 24 measures the associated gap size 40 (measured gap size) at the four support points 43. The tipping 41 of the closure 14 relative to the container 12 is shown by the arrow. The transmitter 34 is not shown in fig. 6. The edges 38, 39 can be determined just by providing the sensor unit 24 comprising at least one camera. For this purpose, appropriate image analysis algorithms are used, which, depending on the light-dark transition from left to right or from top to bottom, can precisely determine the outermost points (lower edge 38, upper edge 39). It is for the support site 43 that the sensor unit 24 measures the gap size 40. The gap dimension 40 is formed by the distance between the support point 43 on the lower edge 38 and the associated support point 43 on the upper edge 39 (for example vertically below the support point on the lower edge). This already yields a higher accuracy when detecting the reduced gap 36 by means of only one projection, as in fig. 4.

The four support points 43 of fig. 6 are now also shown in fig. 7. The associated gap size 40 is already measured in the four support points 43 by the sensor unit 24 or determined by image processing, as already described. Fig. 7 shows the height information of the sensor 18 for determining the height profile. For each point of the surface of the closure part 14, the associated height profile is determined. The height profile is visible in fig. 7 by means of a color scale related to the height. The relatively light sections have a high height, meaning that they are spaced more from the upper edge of the container 12, while the darker areas are located closer to the upper edge of the container 12.

In the following step, the outer edge 49 of the closure part 14 is determined. This occurs, for example, if the general geometry of the closure 14 is known, in that the general geometry, for example a circle or an ellipse, is inserted into the support region 43. Which geometrically defines the outer edge 49 of the closure 14. Alternatively, it is possible to determine the course of the entire outer edge 49 of the closure 14 by means of the height profile of the surface of the closure 14. Here, it is assumed that the outer edge 49 is present at a location at which a very large height profile change occurs.

The course of the outer edge 49 of the closure part 14 is now used to interpolate (interpolate) the quality criterion (for example the gap size 40 at the corresponding location of the outer edge 49) to be determined by the evaluation unit 23 as a function of the height profile at the associated location of the outer edge 49. The gap dimension 40 measured at the respective support point 43 in the outer edge 49 is associated with the associated height profile. If the outer edge 49 is moved away from the support point 43 in a rising height profile (increasing distance to the upper edge 39 of the container 12), the quality criterion to be determined or the gap size 40 also increases. The increase in the gap size 40 is proportional to the increase in the height profile. The reduction in height profile is associated with a reduction in gap size 40. Accordingly, starting from each support point 43 with the measured gap size 40, the associated gap size 40 is calculated for the entire outer edge 49.

The maximum gap size 47 is then determined from the maximum value of the gap size 40 determined above. The maximum gap size 47 is compared with a limit value to determine whether the closed container 12 is still within the permissible range. Alternatively, it is possible to determine the maximum gap size 47 for the location on the outer edge 49 where the height profile also has a maximum. This may simplify the calculation.

In addition to determining the maximum gap dimension 47, the sensor 18 for determining the height profile can also be used for checking the surface of the closure 14. To this end, the sensed height profile is compared with a desired nominal height profile. In the case of a uniform height profile, it can be concluded that the desired closure 14 is also actually used. The height profile is used as an additional or alternative quality criterion. This facilitates quality control, which is of particular interest to the pharmaceutical industry.

The described device can advantageously be a component of, in particular, a pharmaceutical filling device, in which a so-called fit control (Sitzkontrol) or closure fit control is required. However, the application is not set here.

Claims

1. Device for testing a closure (14), wherein the closure (14) closes a container (12), wherein an evaluation unit (23) is provided for determining a quality criterion, which is a size of a gap between the closure (14) and the container (12), characterized in that at least one sensor (18) is provided for determining a height profile of the closure (14), wherein at least one output signal of the sensor (18) is supplied to the evaluation unit (23), wherein the evaluation unit determines the quality criterion from the output signal of the sensor (18), and wherein at least one sensor unit (24) is provided for measuring the quality criterion at least one support point (43).

2. Device according to claim 1, characterized in that said at least one support point (43) is on the outer edge (49) of the closure (14).

3. The device according to claim 1 or 2, characterized in that at least one output signal of the sensor unit (24) is fed to the evaluation unit (23), which evaluates the quality criterion on the basis of the output signal of the sensor unit (24).

4. A device as claimed in claim 3, characterised in that said analysis processing unit (23) derives said quality criterion on the outer edge (49) of said closure (14) from said output signal of said sensor unit (24).

5. A device as claimed in claim 3, characterized in that the evaluation unit (23) derives the quality criterion from the output signal of the sensor unit (24) away from the support point (43).

6. The device according to claim 1 or 2, characterized in that a quality criterion is determined for at least one location on an outer edge (49) of the closure (14) using the output signal of the sensor (18) or a height profile of the closure (14) at the at least one location.

7. A device according to claim 2, wherein the outer edge (49) of the closure (14) is defined in such a way that the general contour of the surface of the closure (14) is placed in at least one support point (43).

8. A device as in claim 7, wherein the general profile of the surface of the closure (14) is circular or elliptical.

9. Device according to claim 1 or 2, characterized in that, for at least one location on the closing part (14), the evaluation unit (23) determines the quality criterion for the location by interpolation from the corresponding height profile at the at least one location and/or from the quality criterion measured in at least one support location (43).

10. A device according to claim 9, wherein at least one location on the closure (14) is on an outer rim (49) of the closure (14).

11. An arrangement according to claim 1 or 2, characterized in that at least one extreme value is determined from a plurality of quality criteria for comparison with the extreme value.

12. Device according to claim 1 or 2, characterized in that the sensor (18) for determining the height profile of the closure (14) is based on laser triangulation.

13. Method for testing a closure (14), wherein the closure (14) closes a container (12), wherein an evaluation unit (23) determines a quality criterion, which is a gap size (40, 47) between the closure (14) and the container (12), characterized by the following steps:

-at least one sensor (18) determining a height profile of the closure (14),

-said analysis processing unit (23) finds said quality criterion from the output signal of said sensor (18), and

-at least one sensor unit (24) measures at least one quality criterion on at least one support point (43).

14. Method according to claim 13, characterized by the further steps of:

-determining the outer edge (49) and/or the outer edge of the closure (14)

-determining a height profile on an outer edge (49) of the closure (14),

-finding the quality criterion on the outer rim (49) from the height profile.

15. Method according to method claim 13 or 14, comprising the further step of:

-the analysis processing unit (23) finds a quality criterion on the outer edge (49) of the closure (14) from the quality criterion measured on the support point (43).

16. Method according to claim 13 or 14, characterized in that for at least one location on the closure (14) a quality criterion for the at least one location is found by interpolation and/or from a quality criterion measured in at least one support location (43) on the basis of the respective height profile at the at least one location.

17. A method as claimed in claim 16, wherein at least one location on the closure (14) is on an outer rim (49) of the closure (14).